CBS News poll: A new high for those who favor pot legalization

FILE - In this Oct. 3, 2012 file photo, marijuana plants are seen in Chicago where officers say they discovered two football fields worth of pot plants growing on the city's South Side. Illinois lawmakers are again trying to decriminalize the possession of small amounts of marijuana but face strong opposition from law enforcement and anti-pot advocates. (AP Photo/Teresa Crawford, File)

Fifty-six percent of Americans say the use of marijuana should be legal – a new high, and a slight increase from a year ago, according to a poll released by CBS News on Wednesday. Now just 36 percent think it should not be legal, down seven points from last year.

Public opinion on legalizing pot has changed dramatically over the years. In 1979, just 27 percent said marijuana use should be legal. As recently as 2011, a slight majority of Americans opposed legalized marijuana use.